section modulus

hi all

a simple question , when calculate section modulus of stiffener , if the outer

skin of effective plating for sandwich should also be calculated .

thanks

 

Depends on the rules you are working to.
Some allow the full width between stiffeners as the outer flange , Good general practice is to use around 15 times the skin thickness for the flange if you are submitting specific design.

 

i used ISO12215-5, if the outer skin of effective plating for sandwich should also be calculated .

 

Look at 12215-5, article 11.5, table 19, note a).

 

Thank above , but i never know 12215-5 contain article 11, my edition is 12215-5.3(2004-12-18)

can you tell me how to fine article 11 , thank you every much

 

Mine is ISO/FDIS 12215-5:2006(E) 2006-01-03. It is not harmonised standard yet, so it can be diffucult to get. I have it for testing and decleration and can't send a copy.

 

Thank you for your answer, i only want to know if the outer skin of effective plating for sandwich should also be calculated when calculate section modulus of stiffener.

Someone tell me calculate normally include the inner laminate only in the effective plate. This is because the foam core have a very low capacity in distributing the force from the inner laminate to the outer laminate of the sandwich construction.

But i think the sandwich laminate is a integrated system and effective plating extent definition is 20(ti+to), so even if "core with low capacity in distributing the force ", the outer skin play the role in structure.

which is right? if you kown, please tell me answer , thank you for you

 

Yes, you are right, calculate both 20(ti+to). This is also how I realize it.

 

Thank you , i'm a novice. This a good beginning and if you don't mind,

please give me an answer that

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